如果输入值介于数据库值 A 和数据库值 B 之间，则选择数据库值 A

Question

我目前正忙于根据数据库中的价格开发价格计算器。

客户指定所需的宽度和高度，计算器应在数据库中查找相应的产品及其价格。

宽度 = 10 & 高度 = 10：价格 = 20

宽度 = 20 & 高度 = 10：价格 = 30

我现在面临的问题：

但是如果宽度在 10 到 19 的范围内，他应该选择宽度为 10 的价格。如果宽度在 20 到 29 的范围内，他应该选择宽度为 20 的价格。等等等等。

当前 HTML 输入表单：

<form action="Database-Output.php" method="post">

<table width="470" border="0">

  <tr>
    <td>Geef hier de door u gewenste hoogte in:</td>

    <td>
    <input type="number" name="height" width="100" placeholder="Hoogte">
    </td>
  </tr>

  <tr>
    <td>Geef hier de door u gewenste breedte in:</td>

    <td>
    <input type="number" name="width" width="100" placeholder="Breedte">
    </td>
  </tr>

  </table>

<br />
<br />

<input type="submit" value="Bereken prijs">

</form>

当前 PHP 表单（Database-Output.php）

<?PHP

$user_name = "root";
$password = "root";
$database = "addressbook";
$server = "127.0.0.1";

$db_handle = mysql_connect($server, $user_name, $password);
$db_found = mysql_select_db($database, $db_handle);

if ($db_found) {

$SQL = "SELECT * FROM price WHERE height = " . $_POST["height"] . "  AND width = " . $_POST["width"] . "";
$result = mysql_query($SQL);

while ( $db_field = mysql_fetch_assoc($result) ) {

print $db_field['value'] . "<BR>";

}

mysql_close($db_handle);

}
else {

print "Database NOT Found ";
mysql_close($db_handle);

}

?>

数据库包含以下值：

id
value (this is the price)
height
width

打印价格表的示例

http://www.entry-vouwgordijnen.nl/price_table.php

有没有什么方法可以以一种简单易维护的方式做到这一点？

谢谢！

回答

我用下面的代码解决了这个问题：

$width = $_POST['width'];
    // Vaste variabele voor breedte
$height = $_POST['height'];
    // Vaste variabele voor hoogte

// ----------------------------TERUGREKENEN NAAR BENEDEN BREEDTE------------------------------ >> GOED //

if ($width % 10 == 0) { 

$widthrounded = $width;
    // If width ends with a zero, do not round the number

} else {

$widthrounded = ceil($width / 10) * 10 - 10;
    // If width does not ends with a zero, round down the number

}

// ----------------------------TERUGREKENEN NAAR BENEDEN HOOGTE------------------------------- >> GOED //

if ($height % 10 == 0) { 

$heightrounded = $height;
    // If height ends with a zero, do not round the number

} else {

$heightrounded = ceil($height / 10) * 10 - 10;
    // If height does not ends with a zero, round down the number

}

// ----------------------------IF DATABASE FOUND SELECT DB VALUE------------------------------ >> GOED //   

if ($db_found) {

$SQL = "SELECT * FROM price WHERE height = " . $heightrounded . "  AND width = " . $widthrounded . "";
$result = mysql_query($SQL);

while ( $db_field = mysql_fetch_assoc($result) ) {

// ----------------------------PRINT RESULT AND CLOSE DB-------------------------------------- >> GOED //   

print $db_field['value'] . "<BR>";

Answer 1

这是一个非常简单的函数，可以将数字四舍五入，

<?php
$width = $_POST['width'];

$width1 = $width - ($width % 10 - 10);

echo "The number ". $width ." rounded up is ". $width1 ."!"
?>

这个函数会向下取整，

<?php
$value = $_POST['width'];

$value1 = ceil($value / 10) * 10 - 10;

echo "The number ". $value ." rounded down is ". $value1 ."!"
?>

此函数将检查宽度是否包含零，如果是则传递变量，如果不是则向下舍入（strpos 检查字符串中的字符串）；

<?php
$value = $_POST['width'];

if (strpos($value,'0') !== false) {

$SQL = "SELECT * FROM price WHERE height = " . $_POST["height"] . "  AND width = " . $value . "";
$result = mysql_query($SQL);

}
else {
$value1 = ceil($value / 10) * 10 - 10;

$SQL = "SELECT * FROM price WHERE height = " . $_POST["height"] . "  AND width = " . $value1 . "";
$result = mysql_query($SQL);

}

?>

Answer 2

几个if 语句应该可以做到这一点，

$height = $_POST["height"];
$width = $_POST["width"];

if ($width >= 10 && $width <= 19) {
$SQL = "SELECT * FROM price WHERE height = '10'  AND width = '10' ";
$result = mysql_query($SQL);
}

if ($width >= 20 && $width <= 29) {
$SQL = "SELECT * FROM price WHERE height = '10'  AND width = '20' ";
$result = mysql_query($SQL);
}